The present invention relates to methods for the gasification of coal or other carbonaceous material. Gasification occurs through pyrolysis as well as reaction of carbon with oxygen and steam to form hydrogen and the carbon oxide gases. The materials contemplated for use include the various types of coal, e.g. lignite and bituminous, as well as various other solid carbonaceous materials.
Previous coal gasification methods such as the SYNTHANE Process of the Pittsburgh Energy Technology Center in Bruceton, Pennsylvania carry with them the problem of eliminating or minimizing environmental pollutants found in the effluent streams from the processes. One of such streams is the condensate from the product gas which not only contains fine particulate char but significant quantities of ammonia, aromatics and traces of sulfur-bearing compounds. This condensate water is primarily unused steam fed to the gasifier. The condensate can include an immiscible mixture of a water phase containing dissolved organics and an oil phase containing condensed tars that are a mixture of heavy aromatics with boiling points above that of water. One of the difficult problems with the SYNTHANE Process and other coal gasification processes is the treatment or disposal of this effluent stream.